A police leader has said an anti-lockdown protest in which eight officers were injured will be raised with senior management in the Metropolitan Police with "utmost urgency".
Demonstrators hurled bottles as officers attempted to disperse the crowds in Hyde Park on Saturday evening after thousands marched in London protesting against vaccine passports and coronavirus lockdown restrictions.
Photographs posted on social media showed a female police officer bleeding from a cut to her head while another suffered a similar wound on his forehead.
The Met said two officers were taken to hospital, although their injuries are not believed to be serious.
Ken Marsh, chairman of the Metropolitan Police Federation – which represents thousands of rank-and-file Scotland Yard officers – said: "We can assure everyone that we shall be raising the scenes we witnessed in Hyde Park yesterday with senior management in the Metropolitan Police with utmost urgency.
"The safety of our police officers should be top of the agenda. We wish all our injured colleagues a swift recovery and will be supporting them as best as we can."
The protest, which also took place in Oxford Street, came almost two weeks after Covid-19 lockdown restrictions were eased.
Seen at the march were London mayor independent candidates Piers Corbyn and Laurence Fox as well as TV nutritionist and I'm A Celebrity... contestant Gillian McKeith.
Protesters held banners saying "You don’t need proof to know truth" and "We stand for freedom".
The Met said five people were arrested for offences including assault on police and public order offences.
Mr Marsh added: "Peaceful protest may well be the cornerstone of democracy – and police officers have a role in facilitating that – but the scenes we saw in Hyde Park yesterday of a thin blue line of brave and sadly bloodied police officers coming under attack from thugs were anything but peaceful.
"Police officers are human beings who go out every day to keep people safe.
"Many people seem to have forgotten that right now but we will keep reminding them.
"Our colleagues have every right to go home to their families at the end of their shifts. Not to hospital."
Mr Marsh pointed out the country is still in the middle of a pandemic, adding "our unvaccinated police officers deserve greater protection".
Home Secretary Priti Patel said on Twitter: "Our brave police are the best of us and should not be the target of senseless violence by a criminal minority for just doing their job.
"I am getting tough on these thugs and will be doubling the sentence for assault of an emergency worker.
"I wish the officers a speedy recovery."
Meanwhile, an expert said anti-lockdown protesters who touch, shout and shun masks are "at the very least a potential risk" to the spread of coronavirus, adding there is some evidence of mass events having an impact.
NHS workers have described the protests as "disappointing" and "shocking".
Dr Ajay Verma, a consultant gastroenterologist and physician working in Northamptonshire, said: "There is a small minority of people who seem to believe there’s a conspiracy going on, which is upsetting, and the worst thing is they’re putting themselves at risk by gathering in a crowd.
"They’re protesting against the measures they’re driving themselves by gathering in a crowd.
"It is very disappointing, I have to say."
Dr Karan Rajan, an NHS surgeon in Surrey, said: "I suspect it was a significant number of people who are anti-vaxxers and conspiracy theorists who got involved, and yet it’s shocking to see.
"Although we know the vaccination rollout is going ahead nicely and we’re getting back to normal with restrictions easing, it’s still very worrying to see such huge gatherings without masks out in public, basically breaking the law, which is really concerning to see."
Professor Stephen Reicher, from the University of St Andrews and a member of the Scientific Pandemic Insights Group on Behaviours (Spi-B), which advises ministers, said counties in the US which held Trump rallies saw bigger spikes in infection than those who did not.
He told the PA news agency: "Moreover, the mass election rallies in India and the permission to bring huge religious festivals forward from 2022 to 2021 (the Kumbh Mela at Haridwar) is one explanation for the huge rise of cases in India.
"Much depends on how people behave in these events. If they maintain distance and wear masks, there is little danger.
"If they explicitly ignore restrictions, if they reject masks, stand close together, touch, shout and sing, then – going back to first principles – there is likely to be a risk.
"Given that the anti-lockdown protests do all of these things, they are at the very least a potential risk."